Heat exchange system



Dec. 12, 1933. sc 1,939,415

HEAT EXCHANGE SYSTEM Filed May 4, 1931 r 2 Sheets-Sheet l Inventor Att'y.

' Fyschaub Dec. 12, 1933. F. H. SCHAUB 1,939,415

HEAT EXCHANGE SYSTEM Filed {lay 4, 1931 2 Sheets-Sheet 2 TUMBLER 6 WATER LINE EXCHANGER RECIEVER 4 BOILER Fred H. Sqhaub Att'y.

Patented Dec. 12, 1933 UNITED STATES PATENT OFFICE HEAT EXCHANGE SYSTEM Fred H. Schaub, University City, Mo. Application May 4, 1931. Serial No. 534,821

1 Claim. (01. 122-1) My invention relates to a heat exchange system and particularly to a system in which the water of condensation from steam using machinery or devices of any kind is returned to the steam generator.

One object of my invention is to accomplish the return of the water of condensation to the boiler with minimum loss of heat therefrom.

Another object of my invention is to provide 313 a system that will efficiently utilize water of condensation at different pressures from different forms of machinery, thus avoiding the duplication of systems for handling high and low pressures in the same plant as is common with sys- 1 tems now in use.

Still another object of my invention is to so arrange the system that water may be deliverd thereby to the boiler at a higher temperature than can be eifectively passed through the pump controlling the circulation of water in the system.

In the accompanying drawings, which illustratea heat exchange system made in accordance with my invention, Figure 1 is a front elevation including a portion of the boiler which it supplies; Figure 2 is an end elevation; Figure 3 is a longitudinal section through the preheating unit or heat exchange proper; Figure 4 is a section taken on the line 4-4 of Figure 3; and Figure 5 isa diagrammatic view.

Referring firstto the diagram (Figure 5), 1 indicates the boiler from which steam is supplied to the various steam using devices of the plant. In the diagram I have shown such devices to be the tumbler, drier, steam board, and press of a laundry but they may be steam using machines or devices of any kind. From the various steam using devices the water of condensation passes through branch pipes, each containing the usual trap 3,-to the main condensate return pipe 2 entering one end of the preheating unit 4. After passing through the unit 4 the condensates pass through pipe 5 to the receiver 6 where make-up water is added to compensate for losses. Water passes from the receiver through pipe '7 to the pump 8 and from the pump through pipe 9 to the preheating unit from. which it is returned to the boiler through pipe 10. The boiler is supplied with an automatic water level switch 11 of any usual kind, such as is used to close an electric circuit, when the water level in the boiler passes below a predetermined level so that the water may be maintained at such level. This switch is interposed in the circuit 12 supplying power to the motor 13 driving the pump so as to automatically start the motor when the water in the boiler falls below the level indicated;

The general operation having been outlined in connection with the diagram, the apparatus will be described in detail, reference being had to 0 Figures 1 to 4. In order to both economize space and reduce the piping and consequent loss of heat to a minimum, the device is arranged as compactly as possible. The preheating unit 4 is mounted in the lower part of a frame 14 with the 5 receiver 6 directly above it in the same frame, and the'pump 8 and its driving motor 13 are situated closely adjacent thereto. The preheater comprises a shell, preferably cylindrical in form, having adjacent its-ends, partitions 15 between which extend tubes 16 through which flow the condensates in their passage from the condensate return pipe 2 to the pipe 5. Feed water passing from pipe 9 to the boiler return pipe 10 circulates around the tubes 16 in the space between the partitions 15 and heat is transferred from the condensates in the tubes to the feed water surrounding them. The lowering of the temperature of the condensate and raising that of the feed water at this point in the circulating system 30 enables me to feed water into the boiler at a higher temperature than that of the feed water passing through the pump which can only be successfully operated when the temperature of the water passing through it is not higher than 5 about 210 degrees Fahr.,--that is, slightly below the boiling point of water at atmospheric pressure. The end of the pipe 9 projects into the shell 4 and is provided with an elbow 17 to prevent the incoming water from striking directly against the tubes 16.

The receiver 6 is supplied with make-up water from any source through a pipe 18 containing a valve 19 controlled by a float 20 in the receiver so that only suflicient make-up water is admitted 5 to maintain the contents of the tank at a predetermined level (indicated by the broken line in Figure 1) The pipe 5 leading from the preheater discharges into the receiver at a point below the water level, thereby forming a seal to prevent the escape of vapor and consequent loss of heat from the condensate passing into the receiver. The receiver is provided with a vent 21 so that its contents are under atmospheric pressure. In order to vent any air which may be contained in the condensate, I provide the condensate return pipe 2 with a pipe 22 terminating in a high pressure air vent 23. Although the amount of conden'sate discharged by the valve when venting air is relatively small, I prefer to discharge it into the receiver so that its heat content will not be lost but will be transferred to the liquid in the receiver. An overflow pipe for the receiver is indicated at 24. Both the make-up water pipe 18 and the pipe 7 leading from the receiver to the pump are preferably provided with strainers 25. A check valve 26 is interposed in the pipe 10 to prevent backflow of water from the boiler when the pump is idle. A second check valve 26 is also preferably interposed in the pipe 9 between the pump and the preheater.

Having fully described my invention, what I claim'as new and desire to secure by Letters Patent of the United States is:

In a device of the class described, the combination with steam using devices, of a boiler for supplying said devices, a condensate return from said devices, a heat exchangerhaving a passage for condensates communicating with said condensate return and a feed water passage communicating with the boiler, a vented receiver, a make-up water supply, automatic valve mechanism cooperating with said supply to maintain the water in said receiver at constant level, connections leading from the condensate passage of the heat exchanger and discharging below the water level of said receiver, connections between said receiver and the feed water passage of the' heat exchanger, a pump interposed in said latter named connections, a motor for driving said pump, means controlled by the water level in the boiler for starting and stopping said motor, an air vent passage leading from the condensate return to said receiver, and a pressure air valve controlling the discharge of said air vent.

- FRED H. SCHAUB. 

